Signaling system



Oct. 4; 1932. l. R. WEIR ET AL 1,880,568

SIGNALING SYSTEM Filed Aug. 27. 1930 Inventovs: Irvin R.Weim, L cgus W. RLch ar'dson',

Their Attorney.

Patented Get. 4, 1932 STA l UH

IRVIN R. VJEIR, OF SCHENECTADY, AND LYCURGUS W. RICHARDSON, OF SCOTIA, NEW YORK, ASSIGNORS TO GENERAL ELECTRIC COMEANY, A CORPORATION OF NEW YORK SIGNALING SYSTEM 7 Application filed August 27, 1930, Serial No. 478,134.

Our invention relates to high frequency signaling systems and especially to high irequency systems for operation at shortwave lengths. till more particularly our invention relates to amplifiers which are adapted for use in systems for the transmission of large amounts of power at short wave lengths and it deals more specifically with the me chanical construction and assembly of the apparatus comprising the amplifier circuit.

Some of the greater diiiiculties encountered in the construction of transmitting systems for operation at short wave lengths have been found to reside in the mechanical structure and assembly of the apparatus comprising the transmitting circuit. The circuits themselves, in many instances, may be those used in systems which operate at long wave lengths and hence no additional difiiculties are encountered in connection therewith. However, at the shorter .wave lengths, as for example at wave lengths less than a hundred meters the effect of capacity existing in and between the difierent components of the circuit and between the components of the circuit and surrounding objects, as well as the inductance of the necessary connecting leads and the like, lead to disturbances and chiliculties which necessitate special considerati on of the mechanical structure and assembly of the apparatus.

Our present invention relates more particularly to high power amplifiers of the push pull type and it has for one of its objects to provide an improved structure and arrangement of condensers employed particularly in the circuits associated with the anodes of the discharge devices of amplifiers of the type indicated.

A further object of the invention is to provide a novel and improved structure of the anode circuits employed in connection with electron discharge devices of the liquid cooled type.

A further object of the invention is to provide an anode circuit condenser assembly characterized by increased compactness of the assembly and facility of control of the individual condensers.

The novel features which we believe to be characteristic of our invention are set forth with particularity in the appended claims. Cur invention itself, however, both as to its organization and method of operation together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. 1 represents a perspective view of a hi h frequency amplifier constructed in accordance with our invention; Fig. 2 of the drawing represents a modification of the arrangement shown in Fig. 1; and Fig. 3 indicates a detail thereof.

Referring to the drawing, we have shown at 1 and 2 electron discharge devices of the water, or liquid cooled type, these devices having liquid cooling jackets 8 surrounding and conductively associated with the anode structure of the discharge device. cooling jackets are directly mounted upon conducting plates 4iwhich in turn are supported by additional plates 5, 6, 7 and 8, these plates all extending parallel with each other. These plates are in turn supported from the base of the housing (not shown) in which the signal system is enclosed by means of suitable insulating supports 9 of which only two are shown in the drawin Of course as many of these supports as desired properly to support the structure may be employed, the supports being arranged in any suitable manner. To reduce losses, however, through the supports, the number employed should be a minimum consistent with rigidity of the structure. The parallel plates 5, 6, 7 and 8 comprise the framework upon which the condensers which are associated with the anode circuits of the discharge de vices 1 and 2 are assembled.

In a well known push pull arrangement the anode circuit of the discharge device is tuned by means of an inductance connected between the two anodes of the discharge devices and a condenser connected in parallel to the inductance. In some cases neutralizing condensers are also employed, one of These frequency electromotive force is supplied from the anode circuit of the one device to the grid of the opposite device sufficient to neutralize the electromotive force supplied from the anode of said opposite device to the grid thereof through its inter-electrode capacity.

In accordance with our present invention all of these condensers areassembled side by side upon the four supporting plates 5, 6, 7 and 8. The anode tuning inductance is represented in the drawing at 10, this inductance being arranged opposite the anode tuning condenser and comprising a coil of hollow tubing arranged to form a double passage for the flow of cooling liquid for the anodes.

Thus, as shown, inlet pipes 11 and outlet pipes 12 are associated with each of the cooling jackets of the discharge devices, the outer ends of these pipesterminating in a connecting block 13. Each of the opposite halves of the coil 10 comprises a passage for coolingliquidrin each direction, the outer ends terminating in plates 14 arranged to be detachably secured to the plates 13. Each of the two passages ortubing sections comprising each of the opposite halves of the coil 10 also terminate at the central point of the coil in a coupling member 15, this member being arranged to be detachably secured.

to an additional coupling member 16, which is supported from the base by means of insulating supports 17, the coupling members 15 and 16 being adapted to form a liquid tight coupling for each of the passages. Thus cooling liquid flows from each of the tubing sections 18 and 19 through the opposite halves of the coil to the bottom of the respective cooling jacket and thence from the top of the water jackets through the pipes 12 and the sections 20 to the outlet at the central point of the coil.

Thus the coupling members 13, 14, 15 and 16 comprise a convenient means whereby coils of different dimensions and difi'erent numbers of turns may be associated with the cooling jackets of the discharge devices thereby to vary the amount of inductance included in the oscillatory circuit of the amplifier.

Further means is provided for effecting small, or fine, variations in inductance of the coil 10, this means comp-rising the conducting disc 21 arranged within the coil,

this member being arranged to vary in position with respect to the turns of the coil by means of a suitable rotatable rod 22 upon which is mounted, this rod extending through the coupling members 15 and 16. Any suitable means not shown may be employed to control the rod 22 from the position, as in front of the transmitter panel, from which the other controls of the trans mitter are operated.

ed to operate. In accordance with our inven:

tion the condenser is so constructed that during normal operation it has a certain fixed component of capacity and an additional variable component of capacity. The fixed component of capacity may be changed as desired between different periods of operation of the system thereby to change the wave length at which the system operates. Thus as shown in the drawing mounted upon the plate 7 are a plurality of additional plates, or electrode members, 23, 24, 25 and 26 which are removably secured to the plate 7 and which project toward the plate 6. Similarly mounted upon the plate 6 are a plurality of plates 27, 28, 29, 30 and 31. All of these plates are arranged to be removably secured to the respective plates 6 and 7 by means of screws certain of which are indicated at 32. Thus the fixed component of capacity may be varied by removing as many as desired of these plates.

The arrangement is such that the fixed component of capacity may be adjusted at fairly close to desired values by proper selection of the numberv of plates used and by properly positioning the plates with respect to each other upon the plates 6 and 7. Of course when only a few of the plates are employed they may be spaced with respect to their broadside relation as desired to provide the proper amount of capacity.

It will be noticed that the inner plates such as plates 24, 25, 28, 29 and 30 extend substantially across the space'between the plates 6 and 7 and are alternately arranged, whereas the plates 23 and 27 and similarly the plates 26 and 31 are arranged directly opposite each other and are of about equal length.

The purpose of the shorter electrode members 23, 27, and 26 and 31 is to obtain a balanced condition of capacitance between the opposite sides of the structure and ground and nearby conducting objects. Thus for example were the end plate 23 of length equal to that of plate 24; it will be seen that I the capacitance between the coil 10 the midpoint of which is at ground high frequency potential and the right side of the structure would be considerably greater than that between this coil and the left side of the struc- 1,seo,5es 3 ture. Thus an unbalanced condition of the circuit results. It will be readily apparent that a similar consideration applies to the plates 26 and 31 and the disc 33 the purpose of which will presently be indicated.

It will be noticed further that this condenser is construct-ed substantially in the form of a cube since in this form a maximum of capacity is afforded from the space which is employed, or which is available.

In order to provide a component of the capacity of this condenser which is readily variable during operation or the system, we have provided a disc 33 arranged in proximity to the plates 26 and 31 and parallel therewith. This disc is arranged for variable broadside displacement with respect to the plates 26 and 31 by means of a suitable screw thread arrangement arranged within a housing 34 and which is similar to that shown at 35 which will later be described. Thus by shifting the plate back and forth by means of the screw thread arrangement the capacity between the two cooling jackets of the discharge devices may be varied as desired over a fairly broad range.

The neutralizing condensers, which may be employed in a circuit extending from the anode of each discharge device to the grid f the opposite discharge device, are assembled in accordance with our invention between the opposite pairs of plates 5 and 6, and 7 and 3 respectively. These condensers are indicated in the drawing at 36 and 37. Each of these condensers, similarly with the condenser of the oscillatory circuit, is arranged to have its capacitance varied over a very wide range and to include a component which is normally fixed during operation of the transmitter and an additional component which is variable during operation. Thus one of the electrodes of each of these condensers comprises aplurality of conducting members, preferably of the form of rods 38, extending between the plates 5 and 6, and similarly in the condenser 36 between the plates 7 and 8. The outer ends of these rods are adapted to be removably secured to the respective plates 5 and 8 by means of screws indicated, one above another, at 39, the ends lying on top of each other in vertical grooves in the sides of the plates 5, 6, 7 and 8 as inclicated at 40 in the plate 7. The screws 39 preferably press these rods between the plates thereby to make good electrical contact at each end.

The opposite plates of the condensers 36 and 37 are formed by means of electrodes 41 and 42 respectively arranged between the plates 5 and 6, and 7 and 8 respectively, these electrodes comprising plates arranged in a plane parallel with the pile of rods 38. Each of these electrodes is supported from the base of the housing by means of an insulating support 43 and from the front panel by insulating rods 43. Of course any other suitable means for rigidly supporting these electrodes may be employed. The electrode 42 is shown connected to the grid of the discharge device 2 through conductor 44 the opposite end of which is connected to the terminal. 60 of the input oscillatory circuit 45. Aflsim: ilar conductor46 is shown connected to the top of the electrode 41 and broken away for the sake of clearness of the drawing, it of course being apparent that this conductor eX- tends to a terminal similar to the terminal 60 on the opposite side of the grid oscillatory circuit and which is connected to the grid conductor 47.

These electrodes 41 and 42 are of course insulated from any other conducting portion of the respective condenser such as the pile of rods 38, the plates 5 and 6 or the back walls 48 and 49. V i

It will thus be seen that similarly with the condenser of the oscillatory circuit the component of capacity of each of these condensers 36 and 37 which is normally fixed during operation of the transmitter may be variedpit desired by changing the number of rods 38 in the pile of the corresponding condenser.

To provide a means for varying the capacity during operation of the transmitter the discs 50 and 51 are provided in the condensers 37 and 36 respectively, these discs being similar to the disc 33- ofthe condenser of the oscillatory circuit. The disc 50 is shown with a backward extending sleeve 52 which extends through the back wall 48 of the condenser, the sleeve and disc being held against rotation by a longitudinal screw and slot 53. This sleeve is provided with an internal thread which cooperates with an external thread upon a rod 54 which is controlled by a non-conducting rod 55. Thus by rotation of the rod 55 the disc 50 may be displaced with respect to the electrode 41. It will of course be understood that the discs 33 and 51 are provided with similar non-conducting rods which extend through the panel of the transmitter housing thereby to permit these discs to be adjusted as desired during operation of the transmitter and without danger to the operator.

The grid oscillatory circuit of the transmit ter is made up of an inductance coil 10 connected between the grids of the two discharge devices and having a condenser 56 connected in parallel therewith. The inductance 10 may be varied if desired by means of a disc 21 arranged therein. The condenser 56 may be one of any suitable construction but as shown is made up in a manner somewhat similar to the condenser of the anode oscillatory circuit previously described. This oscillatory circuit is arranged to be supported bymeans of supports 57 from the upper portion of the housing. T g

It will be noticed that the end plates of the condenser.

the condenser56 extend substantially across This is because in the grid circuit the arrangement of adjacent components of the circuit is such that the resulting capacity unbalance is negligible.

On each side of the condenser 56 is shown an insulating piece 59 upon which is mounted the terminal brackets 60 to which connections are made. The left end of this bracket is conductively connected to the coil 10 and the right end is connected to the conducting portion of the condenser 56 by a removable foot member 61 and screw. By removing these members 61 the condenser 56 may be entirely disconnected from the circuit. 7 Cathode conductors 58 are shown extending from the top of each of the discharge devices, these conductors having clips attached thereto for the connection of supply leads. Each of these conductors is connected to ground through a capacitance enclosed in containers supported on conducting plate 63 which is supported from the housing by conducting member 64. The midpoint of each of these condensers is connected to the support 63, 6 1. Similarly the opposite sides of condenser 56 and the midpoint of coil 10 are connected to ground through condensers 65, 66 and 67 respectively.

In practice this condenser assembly is so located with respect to the tubes and condenser 56 as to obtain a minimum length of connecting leads. The perspective and proportions ofthe drawing are such as to clearly show the various components of the system.

For simplicity of the drawing the high frequency input circuit, load circuit and the direct current energy supply circuits have not been shown, it being sufficient to state that the direct current sources forenergizing the grids and anodes of the discharge devices may be connected between the cathodes and the midpoints of coils 10 and 10 respectively. The high frequency input and output circuits may be coupled, or connected, respectively to the coils in any desired manner.

It is frequently desirable in connection withamplifiers of the type described to so arrange the circuit that the anode circuit is somewhat inductive at the frequency of oscillations produced, whereas the grid circuit is somewhat capacitive with res ect to these oscillations. It is likewise desirable in order to prevent the production of parasitic oscillations and harmonics of the oscillations to be amplified, to connect an additional inductance in the circuit between the oscillatory circuit and the anode of the discharge device.

Further, it is desirable to have this induc-.

tance included in the neutralizing circuit of the system. In Fig. 2, we have shown an arrangement whereby these advantages are accomplished.

Referring to Fig. 2, wehave shown the plate 7 having the condenser electrode members 23, 24, 25, 26 assembled uponone side and a modified form of neutralizing condenser 36 mounted upon the opposite side,

the modified form of neutralizing condenser being desirable when a plurality of discharge devices connected in parallel as shown are employed. It will be noticed that an additional electrode 68 is included in this condenser.

The cooling jackets of the discharge devices are shown connected in series and having the outer ends of their inlet and outlet pipes 11 and 12 terminated in a coupling plate 13. The coil 10 for use in this arrangement is as indicated in Fig. 1 and is coupled to pipes 11 and 12 by means of the plates 13 and 1 1. The plates 13 and 1a of this modification are separated, as better shown in Fig. 3, by aninsulating block 59 provided with passages 69 and 70 for the flow of cooling liquid. The additional inductance may take the form of a solid helical conductor 71 arranged about this coupling block and having its opposite ends electrically connected to the plates 13 and 14. The resistance of water, when employed as cooling liquid, in the passages 69 and 70 is sufiiciently great to permit the inductance of the helical coil 62 to be effective for the purpose indicated.

As indicated in Fig. 2 the neutralizing condenser and condenser 23-31 are insulated from the cooling jacks of the discharge devices, the discharge devices being suitably held in place by conducting member 7 2 which is supported on insulating members similar to 9. The plate 7 is conductively connected to coil 10 by bar 73 at a point between coil 10 and coil 71. Thus the inductance of coil 71 is included in both the anode tuning circuit'and the neutralizing circuit. The grid circuits may of course be made properly capacitive by use of the condensers 65 and 66, by properly positioning the components of the filament circuit with respect to the conductors connected to the grid.

As thus arranged it will be seen that the condenser assembly is characterized by great compactness and facility of control, the simple screw thread arrangement controlled from the adjacent side of the housing, which may be the control panel, serving the purpose. The nonconducting rods 55 which are grounded at the panel end, through means not shown, protect the operator from the high voltages of the condensers. Each of the neutralizing condensers comprises a substantially enclosed unit and are of such construction that variations therein have practically no effect upon the tuning of the system. If

desired, top and bottom plates may be empl yed more completely to enclose these units. Further the outer electrodes of these condensers compriseplates which serve as mounting, or supporting members for the transmitter.

While we have shown particular embodiments of our invention, it will of course be understood that wedo not wish to be limited thereto since many modifications may be made both in the arrangement shown and in the instrumentalities employed. We therefore contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of our invention.

lVhat we claim as new and desire to secure by Letters Patent of the United States, is,-

1. The combination, in a high frequency transmitting system, of a pair of electron discharge devices spaced apart, means connecting said discharge devices in push pull relation, said means comprising a pair of substantially parallel conducting plates, one of said discharge devices being mounted upon and conductively connected with each of said plates, and additional plates extending from each of said plates toward the other plate to form a condenser connected between said discharge devices.

2. The combination, in a high frequency transmitting system, of a pair of electron discharge devices spaced apart, means connecting said discharge devices in push pull relation, said means including a condenser connected between said discharge devices, said condenser comprising a pair of conducting plates, each plate being arranged adjacent to and connected with one of said discharge devices, and electrode members extending from each of said plates toward the other plate, an inductance coil connected between said discharge devices, and a connection between themidpoint of said coil and the cathodes of said discharge devices, said electrode members being so arranged that substantially equal capacitance exists between each side of said condenser and said cathodes.

3. In a high frequency transmitter, a condenser assembly comprising, a pair of centrally disposed parallel plates, conducting members extending from each of said plates toward the other to form a condenser, an additional condenser arranged on the side of each plate opposite said members, each of said additional condensers comprising a conducting member extending at right angles to said plate, and additional adjusting plates, one of said adjusting plates being arranged parallel with and opposite each of said conducting members and another of said adjusting plates being arranged parallel with and opposite the first mentioned conducting members, each of said adjusting plates being arranged for broadside displacement with respect to the respective conducting member.

4. The combination, in a high frequency transmitter, a pair of electron discharge devices, each of said devices having an anode and grid, means connecting said devices in push pull relation, said means comprising two oppositely disposed pairs of parallel plates, one of said discharge devices being arranged adjacent each of said pairs of plates,

the plates of each pair being conductively connected together and to the anode of the adjacent discharge device and comprising an of the discharge device adjacent the opposite pair whereby neutralizing condensers for said transmitter are formed, and'an additional condenser connected between the anode of said discharge devices comprising conducting electrode members mounted upon the inner plate of each pair and extending toward the other pair. I

5. The combination, in a high frequency transmitter, a pair of electron discharge devices, each of said devices having an anode and grid, means connecting said devices in push pull relation, said means comprising two oppositely disposed pairs of parallel plates, one of said discharge devices being arranged adjacent each of said pairs of plates, the plates of each pair being conductively connected together and tothe anode of the adjacent discharge device and comprising an electrode of a condenser, an additional electrode arranged between the plates of each pair and conductively connected to the'grid of the discharge device adjacent the opposite pair whereby neutralizing con densers for said transmitter are formed, an additional condenser connected between the anode of said discharge devices comprising conducting electrode members mounted upon the inner plate of each pair andextending toward the other pair and an adjusting plate for each of said condensers, each of said plates being mounted adjacent an electrode member of the respective condenser and arranged for broadside displacement with respect thereto.

6. The combination, in a high frequency transmitter of a pair of electron discharge devices spaced apart, each of said devices having a cooling jacket, means connecting said devices in push pull relation comprising a condenser arranged between said discharge devices, an additional condenser mounted upon each of the opposite sides of said'first condenser adjacent said discharge devices, one plate of each of said additional condensers and the adjacent plate of the first mentioned condenser being conductively con- 7. The combination, in a high frequency transmitter of a plurality of electron discharge devices, means connecting said discharge devices to amplify oscillations tobe transmitted, said means comprising a condenser mounted adjacent the anode of one of said discharge devices having a pair of oppositely disposed plates, a plurality of conducting members arranged to be removably secured between said plates thereby to provide a course adjustment of the capacity of said condenser, and an additional plate arranged for adjustable broadside displacement with respect to said members to provide fine adj ustmentof capacity of said condenser, said condenser being connected between the anode of the discharge device adjacent to which it is mounted and an electrode of the other discharge device.

8. The combination, in a high frequency transmitter, of an electron discharge device having a liquid cooling jacket, an inductance comprising conducting tubing arranged in series with said water jackets with respect to flow of cooling liquid, and, an additional inductance coil interposed in series electrical relation between said water jacket and said inductance.

9. The combination, in a high frequency transmitter, of a pair of electron discharge devices, each of said devices having liquid cooling jackets, means connecting said devices in push pull relation, saidmeans comprising a liquid carrying tubing having inductance connected in series with said cooling jackets with respect to fiow of cooling liquid, a condenser arranged symmetrically between said discharge devices, an additional condenser arranged upon each of the opposite sides of said first condenser and in proximity to a respective discharge device, a connection between said condensers and said liquid carrying inductance, said inductance forming an oscillatory circuit with the capacity of said first condenser, and an additional inductance interposed between said connection and each of said cooling jackets, said condensers being electrically insulated from said cooling jackets except through said additional inductance.

10. The combination, in a high frequency transmitting system, of a pair of oppositely disposed electron discharge devices, supports therefor, and means connecting said devices in push pull relation, said means comprising a condenser arranged between said discharge devices having opposite parallel plate like electrode members mounted respectively upon said supports of said dis charge devices, each of said plate like electrode members extending from the support upon which it is mounted toward the opposite discharge device.

11. The combination,

in a high frequency transmitting system, or"

a pair of oppositely disposed electron discharge devices, supports therefor, means connecting said devices in push pull relation, said means comprising a condenser arranged between said discharge devices having opposite parallel plate like electrode members mounted respectively upon said supports of said discharge devices, each of said plate like electrode members extending from the support upon which it is mounted toward the opposite discharge device, and means for varying the capacitance the support upon which it is mounted to- .ward the opposite discharge device, said'opposite parallel plate like electrode members forming opposite electrodes of said condenser, and each of said plate like electrode members being removable from said support thereby to Vary the capacity of said condenser.

13. The combination, in a high frequency transmitting system, of a pair of electron discharge devices, a pair of oppositely disposed condensers, each of said condensers being arranged to support one of said discharge devices, and an additional condenser comprising at least one conducting plate mounted upon each of said first condensers in parallel relation and extending from the condenser upon which it is mounted toward the other condenser, said plates forming opposite electrodes of said additional condenser. 1

14L. The combination, in a' high frequency transmitting system, or a pair of electron discharge devices, a pair of oppositely dis in parallel relation and extending from the condenser upon which it is mounted toward the other condenser, said plates forming opposite electrodes of said additional condenser, and each of said condensers including a plate like electrode arranged for variable broadside displacement with respect to the direc-' tion of said plates.

In witness whereof, we have hereunto set our hands this 26th day of August, 1930.

V IRVIN R. WEIR.

LYCURGUS W. RICHARDSON. 

